The invention relates generally to the detection and classification of objects in an image, and more particularly to a method of fusing outputs from multiple detection and classification schemes in order to reduce false alarms.
Many minehunting sonar systems employ high-resolution side-looking sonars that are effective at detecting and classifying bottom-located sea mines in the complex littoral environment. However, these shallow-water regions are also filled with natural, biologic and man-made objects that generate mine-like sonar returns which, in turn, cause many false detection alarms. Accordingly, there has been much research and development of detection and classification sonar processing schemes that can reduce alarms while still maintaining a high probability of mine detection and classification.
Since much of the research and development of detection and classification schemes is carried out by independent or even competitive entities, the various detection and classification schemes generally involve significantly different technical approaches. Here, the phrase xe2x80x9csignificantly different approachesxe2x80x9d means that the algorithms used by the schemes are based on different mathematical, geometrical and statistical theories. Each approach effectively constrains its algorithms (i.e., sequence of data processing steps) by predisposing (or prejudicing) the way it views the data representing the object it is trying to classify. This results in feature spaces and class boundaries that are constructed in very different ways by each algorithm. Thus, each algorithm is keying on substantially different characteristics of mines so that the ultimate performance of a given sensor in a given environment is predicated on the choice of a detection and classification scheme.
Accordingly, it is an object of the present invention to reduce false alarms output by target detection and classification schemes.
Another object of the present invention is to take advantage of the different technical approaches used by a variety of detection and classification schemes in order to reduce false alarms.
A still further object of the present invention is to provide a method of detection and classification that makes simultaneous use of multiple detection and classification schemes.
Still another object of the present invention is to provide a method of reducing the number of false detection alarms produced by a sonar system operating in a littoral region.
Other objects and advantages of the present invention will become more obvious hereinafter in the specification and drawings.
In accordance with the present invention, a method of fusing outputs from multiple detection/classification (D/C) schemes is provided. Each of a plurality of D/C schemes provides output scores for an area of interest. Each output score corresponds to a known location in the area of interest and indicates a degree of confidence with respect to a detection of a target at the known location. The output scores are normalized to form normalized output scores associated with each of the D/C schemes. Each of the normalized output scores is categorized into a group based on the known location associated therewith. The normalized output scores for each group are fused in accordance with a fusion rule.